Their mother, Jamie Marie Hicks, 43, homeschooled them. They played inside the yellow concrete block house, or in the yard.

Their isolation masked extreme abuse, Tampa police said Friday.

Over eight years, Hicks hit the children with various objects, choked them to the point of unconsciousness, held their heads under water, fed them spoiled food and withheld food from them for as long as three days, police say.

She would make her children regurgitate food, then force them to eat it, police say. She would punish them for "stealing" food. Sometimes she would make her oldest sons — twin 16-year-olds — stand still for hours, naked.

At some point, the Florida Department of Children and Families investigated the family, but the agency would not provide details Friday. That case was closed. Tampa police say they became aware of the abuse this week after two of the children ran away.

On Thursday, a pediatric nurse declared the twins malnourished. One was 88 pounds and another 94. They should be 135 pounds, authorities say. They were taken to a hospital.

Police have charged Hicks with two counts of aggravated child abuse and two counts of child neglect. The twins' stepfather, Vernon Courtney Lovell, 53, faces two counts of child neglect. Police say he knew of the abuse and never reported it.

Teachers are required to report suspected abuse, but these children's only teacher was Hicks. Parents who homeschool, like Hicks, must file paperwork with their county's school district, keep a portfolio of records and submit an annual evaluation. There are no in-person visits from school officials.

The criminal charges stem from the abuse of the twins, who were the oldest children in the family. Police expect more charges as medical reports come back on the younger children.

"Seven of the eight children gave the same accounts," said Tampa police spokeswoman Laura McElroy.

That includes the twins, as well as four other boys — ages 4, 7, 10 and 13 — and one girl, 12. The only one who didn't talk to police was the youngest, a 2-year-old girl.

Though DCF had previously investigated the family, they had no ongoing involvement with them and there was no case plan, said DCF spokeswoman Natalie Harrell.

Police say their involvement began at 4:41 p.m Tuesday, when Hicks called 911 to report that her 13- and 10-year-old sons were missing. They had run away from their home at 1414 E Annie St., which is just north of Sulphur Springs, police say.

Authorities found them about four hours later, walking along U.S. 41 near the Pasco County line.

When police initially talked to the children inside the home, there were no obvious signs of abuse. Food appeared to be available and the children were clothed and did not talk about any problems, McElroy said.

Still, there were "red flags" that prompted police to investigate further and to call the Child Protective Investigations Division of the Hillsborough County Sheriff's Office, which DCF contracts with in Hillsborough, McElroy said.

Once investigators got the children outside of the home, they heard consistent tales of horror, she said. At Mary Lee's House in Tampa, which houses several child welfare groups, the children separately gave similar accounts.

The twins told authorities that sometimes, when their mother would make them stand naked, she would pick them up by their genitals.

DCF is sheltering all eight children and now has an open investigation into the situation.

Lovell has lived with Hicks and her children for 13 years, police say. They share some children together, though the twins have the last name of Hicks' ex-husband, who passed away in 2010.

The twins' paternal grandmother became upset when a reporter reached her by phone at her Oregon home Friday. She said she had only casually met Hicks before and had no idea about any abuse. She said she would contact authorities, then hung up.

The family has rented their four-bedroom, 1,500-square-foot home off Busch Boulevard for several years, neighbors say. On Friday, many expressed surprise at the allegations, saying that Hicks appeared to be a good mother.

She often talked about homeschooling her children and would play with them in their yard. She never let them outside of the metal gate surrounding their home, but that did not strike neighbors as odd.

"I just feel like some parents are protective," said Lakendrick Mills, 33, who lives next door. "She seemed like a good mom — 100 percent with her kids all the time."

One neighbor — 18-year-old Tedajah Bell — said she spent some time with the family inside their home. She said Hicks would give her snacks and play educational games with her and the other children. She gave math advice.

"She's nice," said Bell, a senior at Jefferson High School.

Bell would usually play with Hicks' younger children — but not the 16-year-old boys, who she described as "skinny and pale." They were always silent, she said.

Times news researcher John Martin and staff writers Dan Sullivan and Marlene Sokol contributed to this report. Jessica Vander Velde can be reached at jvandervelde@tampabay.com or (813) 226-3433.